1. Field of the Invention
The invention relates to a roof headliner structure in which a curtain airbag for a vehicle is housed.
2. Description of Related Art
Japanese Patent Application Publication No. 2014-037216 (JP 2014-037216 A) describes a technique for reducing the occurrence of breakage of an A-pillar garnish. Specifically, as illustrated in FIG. 5, a clip seat 4a is disposed on the opposite side of a curtain shield airbag (CSA) (hereinafter, simply referred to as “curtain airbag”) 2 from the side on which the curtain airbag 2 deploys. A tilted portion 4b is formed at a junction between a front wall and a top wall of the clip seat 4a. The tilted portion 4b is tilted in such a direction that the seating surface of the clip seat 4a is reduced. This structure allows the clip seat 4a to easily pivot about an A-pillar inner panel 7 upon deployment of the curtain airbag 2. Thus, a held portion 5a of a tether clip 5 easily comes out of a through-hole 4c of the clip seat 4a. As a result, the occurrence of breakage of an A-pillar garnish 4 is reduced. According to JP 2014-037216 A, the curtain airbag 2 is housed not only in a roof headliner (ceiling material) but also in the A-pillar garnish 4.
FIG. 6 illustrates the flow of force during deployment of the curtain airbag 2. In other words, a force of deployment of the curtain airbag 2, which is generated by the gas from an inflator, is transmitted to the roof headliner through a route R2. In addition, the force of deployment of the curtain airbag 2 is transmitted directly to a terminal end of the A-pillar garnish 4 through a route R1. The force transmitted to the terminal end of the A-pillar garnish 4 is transmitted to the clip seat 4a of the A-pillar garnish 4 through a route R3, and serves as a force for detaching the tether clip 5 from the clip seat 4a (load required to remove the held portion 5a from the clip seat 4a).
However, the conventional structure has room for improvement regarding the following point. The roof headliner first opens toward the inside of a vehicle cabin, and then the curtain airbag 2 starts deploying with the A-pillar garnish 4 remaining. In this case, before the held portion 5a of the tether clip 5 is detached from the clip seat 4a, the force of deployment of the curtain airbag 2 may be applied directly to the A-pillar garnish 4, which may result in breakage (fracture) of the A-pillar garnish 4.